Study Guide · Bucket 4 of 7
Networking & Content Delivery
Networking scary lagta hai but reality yeh hai — tumhe network engineer nahi, sirf 'systems ko connect karna' aana chahiye.
Context
Yahan pattern yaad rakho: VPC se sab secure rakho, Load Balancer se traffic distribute karo, Route 53 se DNS handle karo, CloudFront se speed do, aur API Gateway se service ko expose karo. Yehi modern AWS architecture ka backbone hai.Amazon VPCVirtual Private Cloud
What
Tumhara apna private network AWS ke andar — jaise ek building jisme koi bina permission enter/exit nahi kar sakta.
Why
Security aur isolation ke liye. Database ko seedha internet se access nahi hona chahiye — VPC woh protective layer deta hai.
How
IP range define karo (CIDR block) -> Subnets banao: Public (internet-facing, jaise Load Balancer) aur Private (databases, internal services) -> Route Tables se traffic flow control karo.
Skill
Basic IP/CIDR concepts, advanced routing zaroori nahi.
- CIDR blocks (calculator use karo, memorize mat karo)
- Public vs Private subnets
- Internet Gateway
- NAT Gateway (private subnet ko outbound internet deta hai, inbound nahi)
- Security Groups vs NACLs (firewall rules)
Elastic Load Balancing (ELB)ALB / NLB
What
Incoming traffic ko multiple backend servers mein distribute karta hai.
Why
High availability ke liye — agar ek server down ho jaaye, traffic doosre pe chala jaaye. SSL termination aur health checks bhi handle karta hai.
How
Load balancer banao -> targets add karo (backend servers) -> routing strategy define karo. Application Load Balancer (ALB) = Layer 7, web traffic ke liye. Network Load Balancer (NLB) = Layer 4, baaki sab (ultra-low latency) ke liye.
Skill
Concept-level.
- ALB vs NLB
- Health checks
- SSL/TLS termination
Amazon Route 53DNS service
What
AWS ka DNS (Domain Name System) service — domain names ko IP addresses se map karta hai.
Why
Har application ko ek readable domain chahiye (google.com), jo eventually kisi Load Balancer/server ki IP ki taraf point kare.
How
Domain register karo (ya existing domain use karo) -> Hosted Zone banao -> DNS records add karo -> Route 53 ko DNS provider set karo.
Skill
Concept-level.
- Hosted zones
- DNS records (A, CNAME, etc.)
Amazon CloudFrontCDN
What
Content Delivery Network — content ko duniya bhar ke edge locations pe cache karta hai.
Why
Speed. US ke user ko agar India ke server se content chahiye, seedha request bhejna slow hoga — CloudFront paas ke edge location se serve karta hai.
How
CloudFront distribution banao, origin set karo (S3, ALB, ya koi bhi backend) -> users nearest edge location se serve hote hain.
Skill
Concept-level.
- Edge locations
- Caching / TTL
Amazon API GatewayAPI management
What
REST/HTTP/WebSocket APIs create, publish, aur secure karne ka managed service.
Why
Jab frontend ko backend se baat karni ho (specially Lambda se), API Gateway beech mein sit karta hai aur authentication, rate limiting sab handle karta hai.
How
API endpoints define karo -> backend se connect karo (Lambda functions ya EC2 servers) -> deploy karo -> managed API mil jaata hai.
Skill
Concept + basic REST API design.
- REST vs WebSocket APIs
- Rate limiting
- Auth integration
Real org mein
Real org mein: frontend team kabhi backend server se directly connect nahi karti. Sab API Gateway ke through jaata hai — isse versioning, rate-limiting, aur security ek hi jagah control hoti hai.Key Tasks — is bucket ko 'done' maanne se pehle
- Ek VPC banao with 1 public + 1 private subnet
- Public subnet mein Internet Gateway attach karo, private mein NAT Gateway
- Security Group banao jo sirf port 80/443 allow kare
- ALB banao jo 2 EC2 instances ke beech traffic distribute kare
- VPC ka poora traffic-flow diagram khud bana ke explain kar sako